Glass optical fibers are used extensively in lasers and communications applications. Ideally, glass optical fibers are free of crystals along long lengths of the fibers. Unfortunately, some non-oxide glasses (e.g., chalcogenides, heavy metal fluoride glasses such as zirconium fluoride-barium fluoride-lanthanum fluoride-aluminum fluoride-sodium fluoride known as “ZBLAN”) are subject to crystal formation when produced in unit-gravity (i.e., Earth-based) facilities. While some research has shown that non-oxide glasses have reduced crystal formation when processed in microgravity environments (e.g., space), proposed methods and systems for non-oxide glass optical fiber production have only yielded short lengths of fibers on the order of a meter or two.